Video size calculator. Know the file size before you record.
Calculate video file size for 720p, 1080p, and 4K at 24, 30, or 60fps. Compare H.264 and HEVC side by side so you know exactly what each setting costs.
Estimates based on typical iPhone recording settings. Actual file sizes may vary depending on scene complexity and device model.
How to calculate video file size.
Video file size is bitrate multiplied by duration. Bitrate is measured in megabits per second, and there are 8 bits in a byte:
file size (MB) = bitrate (Mbps) × duration (seconds) ÷ 8The calculator picks a typical bitrate for the resolution, frame rate, and codec you choose, then applies that formula. Real recordings vary a little because the encoder spends more bits on detailed, fast-moving scenes.
Worked example: 10 minutes of 1080p at 30fps
- Typical H.264 bitrate used by the calculator: 8 Mbps
- Duration: 10 minutes = 600 seconds
- 8 × 600 = 4,800 megabits
- 4,800 ÷ 8 = 600 MB (about 60 MB per minute)
The calculator displays sizes in binary units (1 MB = 1,048,576 bytes), so the same clip appears as about 572 MB there.
Starting from a known bitrate or a target file size instead? Use the bitrate calculator. Planning storage on a phone? See how long an iPhone can record with the space you have and the iPhone video settings and formats guide.
Three knobs, one bill.
4K has 4x more pixels than 1080p. More pixels means more data per frame and larger files.
60fps captures twice the frames of 30fps, so cameras record it at a higher bitrate and the file grows accordingly.
HEVC (H.265) is about 50% smaller than H.264 at similar visual quality. It is the iPhone default when the camera format is set to High Efficiency.
| Setting | Per minute | 10 min | 1 hour |
|---|---|---|---|
| 720p @ 30fps | 40 MB | 400 MB | 2.4 GB |
| 1080p @ 30fps | 60 MB | 600 MB | 3.6 GB |
| 1080p @ 60fps | 90 MB | 900 MB | 5.4 GB |
| 4K @ 24fps | 135 MB | 1.35 GB | 8.1 GB |
| 4K @ 30fps | 170 MB | 1.7 GB | 10.2 GB |
| 4K @ 60fps | 400 MB | 4 GB | 24 GB |
HEVC sizes are approximately half these numbers.
Common questions.
- How do you calculate video file size?
- Multiply the bitrate in megabits per second (Mbps) by the duration in seconds, then divide by 8 to convert bits to bytes. For example, 8 Mbps for 10 minutes (600 seconds) is 8 × 600 ÷ 8 = 600 MB. Audio and container overhead add a little on top.
- How accurate is this calculator?
- Estimates are based on typical iPhone recording bitrates. Real files vary with scene complexity: static scenes compress better than fast action, foliage, or water.
- Why is 4K 60fps so much larger than 4K 30fps?
- 60fps captures twice as many frames per second, so the camera records at a much higher bitrate. A 10-minute 4K 60fps clip can easily pass 4 GB.
- What's the difference between H.264 and HEVC?
- HEVC (H.265) is a newer codec that produces files about half the size of H.264 at similar visual quality. iPhones since the iPhone 7 can record HEVC, and it is the default when the camera format is set to High Efficiency.
- How can I reduce my video file sizes?
- Record at a lower resolution or frame rate, or re-encode existing videos to HEVC. HEVCut does this on your iPhone and lets you compare the result before replacing the original.
- Does HEVC play on all devices?
- HEVC plays on iPhones since the iPhone 7, recent Macs, most Android phones from 2018 onward, and Windows 10/11 with the HEVC extension. Older devices can use a free player like VLC.
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HEVCut runs on iPhone, iPad and Mac. Everything stays on-device, offline. Try a few compressions before committing to Pro.
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